Photographic elements



United States Patent 3,312,554 PHOTOGRAPHIC ELEMENTS Hans Max Wagner and Thomas Peter Reginald Maynard, Harrow, Middlesex, England, assignors to Eastman "ice of alkyl vinyl ether with maleic anhydride, or terpolymers of alkyl vinyl ether, ethyl acrylate and maleic anhydride.

We have found that when the polymers of our invention are incorporated in gelatino silver halide emulsions, the maximum density of the dried down layer is increased,

' 5 er g Rochester a corpommm of and that there is a reduction in loss of density on drying. N Drawing Filed Oct 24 19 3 Sen 1 Our invention will be further illustrated by the follow- 3 Claims. (Cl. 96-114) mg pl EXAMPLE 1 This invention relates to certain polymers which are useful additives for photographic gelatino silver halide 10 Reactwn of polyacyylw anhydnde an ethylalanme emulsions, and to photographic silver halide emulsions containing th polymers, Preparation of polyacrylic anhydride: Acrylic anhydride It is well known that certain gelatino silver halide (P p y the method of Bletherten, Smith emulsions lose density as the wet-developed layer is dried. 15 e Lynn, 1961, 21, 1233) Was dissolved It is therefore desirable to provide photographic silver 1h y diOXaIle is a 250 60- r und bott m d halide emulsions which have a reduced tendency to lose flask- Nitrogen Was Passed through the solution and density upon drying. azodiisobutyronitrile (0.4 g.) was added. The flask was One object of our invention is to provide certain polysealed and placed in a thermostated waterbath at 50 C. mers which are useful additives for photographic gelatino 2O eh 48 hours When the P y had Completely P silver halide emulsions. Another object of our invention elpltated- It Was Collected, Washed thoroughly With y is to provide photographic silver halide emulsions having diOXane and dried under Vaellum- The yield Was 16 a reduced tendency to lose density upon drying and after Reaction With ethylalahihei A Solution of Pelyaerylie development. A further object of our invention is to anhy ride g-) in y dimethylformamide provide photographic emulsions which have increased Was added With stirring, While heating on steambath, to maximum density. Other objects will appear herein. a solution of ethylalanihe in y dimethyl' These and other objects of our in ti are formamide (50 cc.). The solution was stirred and heated complished by providing polymers which are th ti on the steambath for 18 hours. It was allowed to cool and product of an ester of an amino acid represented by the th p lym r Was Precipitated y Pouring the Solution into following structural formula: 30 3 liters anhydrous ether, washed with further portions of ether and dried under vacuum. The yield was 15 g. I The polymer was tested for its ability to reduce loss of R OG O R2 density of silver halide emulsions by dissolving in water NIH and adjusting the pH to 6.5. The solution was then added wherein R represents asubstituent selected from the group at the of 30 g m Polymer P ofsllver to consisting of coarse grain bromiodlde emulsion which contained 135 g. of gelatin per mole of silver halide. The mixture was N then coated onto film support. Strips were cut and ex- CHzCH2CO-CH2CH3 posed for l/50 in an intensity scale sensitometer, d CH CH S CH d R represents a b. 40 developed for 3 minutes (at 20 C.) in the following stituent selected from the group consisting of CH developer! CH2CH3 Elon g 2.2 Hydroquinone g 8.8 g Anhydrous sodium sulfate g 72.0 Anhydrous sodium carbonate g 48.0 and Potassium bromide g 4.0 i H Water to 1 1.0 N CHFC 0 CH3 fixed and washed in the usual manner. Densities were with a polymer selected from the group consisting of read while the film was wet and after the film had been polyacrylic anhydride, polymethacrylic anhydride, copolydried in air at 120 F. and 20% RH. Characteristic mers of alkyl vinyl ether (the alkyl groups of which are curves were plotted for the wet and dry film and the from 2-4 carbon atoms) with maleic anhydride, or terdensity differences on drying down were measured at polymers of alkyl vinyl ether (the alkyl group being 2-4 specific densities. Speed was measured as the rel. log carbon atoms), ethyl acrylate and maleic anhydride. (10/ E) where E is the exposure required to produce a In one embodiment of our invention we provide codensity of 0.85 above fog. In addition, two slope criteria polymers of acrylic acid or methacrylic acid with N- were calculated: (1) the toe slopethe slope of a line acrylyl (or N-methacrylic)amino acid esters or dipeptide which joins two points on the curve which are at densities esters, the amino acid esters and dipeptide esters being of 0.25 and 2.0 above fog; and (2) the shoulder slopea those described in the above structural formula. similar criteria where the points are at densities of 1.0 In another embodiment of our invention we provide and 2.5 above fog. Speed, fog and maximum density polymers which are the reaction product of the amino (dry) were also measured. The results are shown in the acid and dipeptide esters described above with copolymers following table:

Slope Dens. loss at Rel. Fog Dmux Speed Dry Toe Shoulder 1.5 2.5 3.5

Control 286 2. 56 2. 94 .10 3. 3 13 40 69 2 Parts polymer Ex. 1 per 9 parts gelatin..." 292 2.82 3. 74 13 4. 3 02 06 20 3 EXAMPLE 2 Reaction product polyacrylic anhydria'e and ethyl glycylglycine The co-polymer was prepared by the method described in Example 1 from ethylglycylglycine (8 g.) and polyacrylic anhydride (6.3 g.). There was obtained 8 g. of an almost colorless water soluble powder. The following results were obtained when tested as in Example 1:

4 EXAMPLE 5 Reaction product of terpoly(ethyl vinyl ether, ethyl acrylate, maleic anhydride) and ethylalanine Slope Dens. loss at Rel. Fog Dmnx Speed Dry Toe Shoulder 1.5 2.5 3.5

Control 286 2. 74 s. 5 0s 3. e0 11 2s 2 Parts polymer Ex. 2 per 9 parts gelatin.-. 290 2. 66 4. 0 .09 4.0 06 18 24 EXAMPLE 3 Reaction product f polymeflmcrylic mlhydride and 20 added. The ar was closed with a lid co taining aorubber ethylglycine seal and placed 1n a thermostated water bath at C. for polymethacrylic anhydride was P p from meth 7 days The solut1on had become v1scous and was precipiacrylic anhydride by the method described in Example 1 tated 1n ether and Washed ihoroughly 1n ether- T1115 P for the preparation of polyacrylic anhydride. This poly- 11161 g) Was then dlssolved 1n dlmethylfofmamide mer (15.4 g.) in 'dimethylformamide (250 cc.) solution (150 ml.) and added with stirring to a solution of ethylwas reacted with freshly prepared ethylglycine (15 g.) in alanine 18 in dimeth lformamide 50 1 Th dimethylformamide (50 cc.) under the conditions of Ex- SoIutiOn i ig on th a bath f 1 e ample 1. A pale cream powder (18 g.) was obtained. e S e m or 2 Ours On testing, as described in Example 1, the following renng throughout thls Penod and the Polymer was P i sults were obtained: 1 3O tated after cooling, by pouring it into ether. It was ashed Slope Dens. loss at Rel. Fog D... Speed Dry Toe Shoulder 1.5 2.5 3.5

Control 286 2. 74 3. 5 .08 3.60 11 2s 46 2 Parts polymer Ex. 3 per 9 parts gelatin 291 2. 92 4. 3 .11 4. 0 04 Nil 12 EXAMPLE 4 with 3 further portions of ether and dried under vacuum. Copolymer 0f methacrylic acid and N-methacrylyl Yield ethylalzmine The polymer was tested as described in Example 1. In

in Example 1 from polymethacrylic anhydride (15.4 g.)

the following table are given the results which were obtained.

Slope Dens. loss at Rel. Fog Dm ax Speed Dry Toe Shoulder 1.5 2.5 3.5

Control 298 2. 66 3. 36 O9 3. 45 14. 26 42 2 Parts polymer Ex. 5 per 9 parts gelatin 293 2. 70 3. 58 07 3. 80 04 18 22 dissolved in dimethylformamide (250 cc.) and ethyl- EXAMPLE 6 Reaction product of c0p0ly(ethyl vinyl ether, maleic anhydride) and ethylglycine Ethyl vinyl ether, which had been washed with water,

dried over solid potassium hydroxide and distilled giving a colorless liquid boiling at 36 C. (40 g.), maleic an- Slope Dens. loss at Rel. Fog Dmax Speed Dry Toe Shoulder 1.5 2.5 3.5

Control 286 2. 74 3. 5 08 3. 6 11 26 46 2 Parts polymer Ex. 4 per 9 parts gelatin 283 2.98 4. 3 .07 4.1 08 06 24 hydride (40 g.) and acetone (400 cc.), were placed in a glass pressure jar. Nitrogen was bubbled through the solution and azodiisobutyronitrile catalyst (0.8 g.) was the method described in Example 5. The yield of amino acid derivative was 16.5 g. This polymer was tested as described in Example 1. The following results were obadded. The jar was closed with a lid containing a rubber tained.

Slope Dens. loss at Rel. Fog Din Speed Dry Toe Shoulder 1.5 2.5 3.5

Control 298 2. 54 2. 88 07 3. 2 72 Parts polymer Ex. 7 per 9 parts gelatin 295 2. 88 4.10 07 3. 9 08 Nil Nil seal and was then placed in a thermostated water bath at EXAMPLE 8 for y? days The i f p y q 15 Reaction product of polymethacrylic anhydride and ethyl and was precipitated by pouring it, with rapld stirrmg, into methionine industrial methylated spirits. After stirring for 15 minutes, the polymer was allowed to settle, the supernatant liquor was decanted and replaced by a fresh portion of methylated spirits (3 l.) and the mixture was stirred for 20 fifteen minutes. The washing process was then repeated.

A copolymer was prepared as described in Example 4 except that ethyl methionine (26.5 g.) was substituted for ethylalanine, and tested as described in Example 1. The following results were obtained:

Slope Dens. loss at Rel. Fog Dmax Speed y Toe Shoulder 1.5 2.5 3.5

Control 284 2. 62 3. 16 .07 3. 35 12 26 4e 2 Parts polymer Ex. 8 per 9 parts gelatin 286 2. 82 3. 74 10 4.10 06 06 16 Finally the fibrous, polymeric material was collected and EXAMPLE 9 dnfid m i Yleld Q Thls polymer had a vlscoslty Reaction product of polyacrylic anhydride and ethyl of 6.0 cs. in a 5% solution 1n acetone. methionine This polymer (10 g.) was dissolved in dimethylformamide (100 ml.) and the solution was added with stirring 35 to a solution of ethylglycine (9 g.) dissolved in dimethylformamide (30 ml.). The solution was heated, while stir- The polymer was prepared and tested as described in Example 1 except that ethyl methionine (26.5 g.) was substituted for ethylalanine. The following results were ring, on a steambath for 2 /2 hours and was then allowed obtained:

Slope Dens. loss at Rel. Fog rnax Speed Dry Toe Shoulder 1.5 2.5 3.5

Control 284 2. 02 3. 16 07 3. 35 12 2e 4s 2 Parts polymer Ex. 9 per 9 parts gelatin-.." 284 3. 12 4. 16 3. 10 Nil 14 to cool and precipitated in ether as described in Example 1. (Yield 14 g). The polymer was tested as in Example 1. The following results were obtained.

Slope Dens. loss at Rel. Fog Dmnx Speed Dry Toe Shoulder 1.5 2.5 3.5

Control 29s 2. 66 3.36 .09 3.45 -.14 .26 -.42 2 Parts polymer Ex. 6 per 9 parts gelatin- 296 2. 80 3. 94 O9 4. [)0 Nil 06 ()4 EXAMPLE 7 60 EXAMPLE 10 Reaction product of terp0ly(ethyl vinyl ether, ethyl acry- Reaction 2? .3 f l lather-male.

late, maleic anhydride) and ethylglycine y n e) an e W me wnme The polymer was prepared and tested as described in A terpolymer was prepared as described in Example 5, Example 6 except that ethyl methionine. (26.5 g.) was and 15 g. were then reacted with ethylglycine (14 g.) by a substituted for ethylglycine with the following results:

Slope Dens. loss at Rel. Fog Dmx Speed 7 y Toe Shoulder 1.5 2.5 3.5

Control 281 2. 54 2. .10 3.25 13 27 -.47 2 Parts polymer Ex. 10 per 9 parts gelatin 283 2. 80 3. 60 11 3. 80 11 18 18 7 EXAMPLE 11 7 Reaction pro-duct of terply(ethylvinyl ether-ethylacrylate-maleic anhydride) and ethyl methionine The polymer was prepared and tested as described in Example except that ethyl methionine (26 g.) was substituted for ethylalanine. The following results were obtained:

Slope Dens. loss at Rel. Fog Druax Speed Dry Toe Shoulder 1.5 2.5 3.5

Control 281 2. 54 2. 90 10 3. 13 27 47 2 Parts polymer Ex. 11 per 9 parts gelatin 271 2. 64 3. 56 10 3.85 16 23 36 EXAMPLE 12 Reaction product of polymethacrylate anhydride and ethylglatam'ate The-polymer was prepared and tested as described in Example 4 except that ethylglutamate (28 g.) was substituted for ethylalanine, with the following results:

Slope Dons. loss at Rel. Fog Dmax Speed Dry Toe Shoulder 1.5 2.5 3.5

Control 281 2. 6 3. 56 .09 3. 56 24 40 60 2 Parts olymer Ex. 12 per 9 parts gelatin.-. 290 2.8 4. 20 10 3. 80 12 24 26 The foregoing examples demonstrate that the polymers The quantity of amino acid or dipeptide ester reacted in accordance with the invention effectively reduce loss with the polymers employed in the invention may vary of density on drying, and also function to increase the maximum density of gelatino silver halide emulsions. Examples 13 and 14 below demonstrate the unexpected nature of our invention in that certain polymers closely related to those of the invention fail to effectively reduce loss of density upon drying of gelatino silver halide emulsions.

EXAMPLE 13 Reaction product of cop0ly(methyl vinyl ether-malcic anhydride) and ethylglycine The above copolymer, having a specific viscosity of 0.1-0.5 was treated with ethylglycine in a manner similar to that described in Example 7 and tested photographically as described in Example 1, with the following results:

over a wide range, and advantageously is in excess of one molar proportion of amino acid or dipeptide ester for each anhydride group present, and preferably is from 1.5-2 molar roportions per each anhydride group of the polymer.

The exact chemical nature of the reaction product is not known, but it is believed that under the conditions in which the polymers are made, one of the carboxyl groups liberated on opening the anhydride ring may form a salt. While preliminary analysis points to the formation of a partial amino acid salt, this has not yet been confirmed.

The molecular weight of the copolymers and terpolymers which are reacted with the amino acid and dipeptide esters may vary over a considerable range, and advantageously is such that a 5% solution of the polymer Slope Dens. loss at Rel. Fog Dmax Speed Dry Toe Shoulder 1.5 2.5 3.5

Control 290 2. 80 3. 6 .07 3. 58 2O 34 60 2 Parts polymer Ex. 13 per 9 parts gelatin.-- 295 2. 76 4. 0 08 4. 00 20 -.40 64 EXAMPLE 14 Reaction product 0 copo ly(ethylene-maleic anhydride) and ethylalanine The above-identified copolymer was treated with ethylalanine and tested in the manner described in Example 1. The following results were obtained: from 1 to 4 parts by weight polymer to 9 parts by weight Slope Dens. loss at Rel. Fog Dru ax Speed Dry Toe Shoulder 1.5 2.5 3.5

Control 287 3. 16 3. 78 07 3. 76 26 44 62 2 Parts polymer Ex. 14 per 9 parts gelatin"- 286 2. 96 4. 10 07 3.90 16 36 48 9 gelatin. The preferred ratio is 1 /3 to 2% by weight polymer to 9 parts by weight gelatin.

Gelatin silver halide emulsions containing the polymer of our invention may be sensitized with any of the well known techniques and additives in emulsion making. The gelatin may contain a plasticizer, such as glycerine, and a gelatin hardener, such as formaldehyde. Other customary photographic emulsion addenda may be present in the emulsion.

This invention has been described in considerable detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. A photographic silver halide emulsion containing the reaction product of an amino acid ester selected from the group consisting of those represented by the following structural formula:

wherein R represents a substituent selected from the group consisting of H; -CH

OH2CH2-C-O-OH2GI-Ia CH CH -SCH and R represents a substituent selected from the group consisting of CH CH CH with a polymer selected from the group consisting of polyacrylic anhydride, polymethacrylic anhydride, copolymers of alkyl vinyl ether, the alkyl groups of which contain from 2-4 carbon atoms, with maleic anhydride, and terpolymers of alkyl vinyl ether, the alkyl groups of which contain 2-4 carbon atoms, ethyl acrylate, and maleic anhydride.

2. A gelatin silver halide emulsion containing the reaction product of an amino acid ester selected from the group consisting of those represented by the following structural formula:

CH CI-I SCH and R represents a substituent selected from the group consisting of CH;,; CH CH with a polymer selected from the group consisting of polyacrylic anhydride, polymethacrylic anhydride, copolymers of alkyl vinyl ether, the alkyl groups of which contain from 2-4 carbon atoms, with maleic anhydride, and terpolymers of alkyl vinyl ether, the alkyl groups of which contain 2-4 carbon atoms, ethyl acrylate, and maleic anhydride, the ratio of said reaction product to the gelatin of the emulsion being from 1 to 4 parts by weight reaction product per 9 parts by Weight gelatin.

3. A gelatin silver halide emulsion containing, per 9 parts by weight gelatin, 1 /3 to 2% parts by weight of the reaction product of polyacrylic anhydride and ethylalanine.

References Cited by the Examiner UNITED STATES PATENTS 2,409,126 10/1946 Kenyon etal.

NORMAN G. TORCHIN, Primary Examiner.

ALEXANDER D. RICCI, Examiner.

R. H. SMITH, Assistant Examiner. 

1. A PHOTOGRAPHIC SILVER HALIDE EMULSION CONTAINING THE REACTION PRODUCT OF AN AMINO ACID ESTER SELECTED FROM THE GROUP CONSISTING OF THOSE REPRESENTED BY THE FOLLOWING STRUCTURAL FORMULA: 